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Amiga runs Michigan schools' heating and air conditioning systems (2015)

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Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#41

Post by cobaltoxide »

whalesalad wrote: post #27
tus666 wrote: post #15

> Hopkins said the system runs on a radio frequency that sends a signal to school buildings, which reply within a matter of seconds with the status of each building. I suspect this is what would be difficult to replace. A bespoke wireless sensor monitoring and communications system, integrated into an old heating/cooling system. Modern system just would not integrate into this, without a lot of work. You would have t…

What makes you say that? A software defined radio could do this pretty easily.

Reminds me of: "We do these things not because they are easy but because we thought they would be easy."

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#42

Post by snerbles »

doobiedowner wrote: post #35
jprd wrote: post #26

Earlier quoted context omitted.

You'd probably be horrified to know what kind of systems still run most of the world's manufacturing, very much including modern chip fabs.

Ladder logic, written by peasants. (signed: control peasant that prefers ST)

Lucky you, my stakeholders would run screaming for the hills whenever they caught a whiff of written code on PLCs. All ladder, all the time.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#44

Post by hoten »

fiddlerwoaroof wrote: post #36
hoten wrote: post #29

Earlier quoted context omitted.

The number of layers added to modern programming and computer systems has gone up significantly since the 80s. It's sensible to claim that a kid from the 80s had far less to learn to be effective in the world of the 80s, than a 20s kid would need today.

Ok, but as far as the users are concerned, do the layers add much value to this use-case?

Likely no, but a kid isn't going to be learning low level systems programming in highschool. Their entry point into the world is programming is going to be high-level, as that has less barrier to entry.

My point is that kids in the 80s interested in computers likely had the skillset to do this job. Kids interested in programming today, they are more likely to be qualified to make the school a website, not program its heating system. I don't doubt some would be able to do it, but the field has grown so much that beginners necessarily must focus on specific areas, and I bet that is not often low level enough to do this job.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#45

Post by NovaDudely »

deadlyllama wrote: post #20

You could retrofit a more modern computer in there. Probably even reverse engineer the radio system and replace it. This would have been done by an enthusiastic high school student with both programming, electronics, maybe some RF knowledge too. Radio amateur? I find these stories kind of sad. Clever system built by someone talented, at a low cost -- replacement with a modern system costed in the millions. Those tale…

Here is Melbourne, Australia our train system used to run on I believe a PDP based system established in 1982 until the mid 2000's when they started a transition to an all new system simply because the hardware was getting too old to maintain.

The intermediate step was to emulate the old systems software on Windows XP machines until all the other signal systems could be upgraded.

https://web.archive.org/web/20201112040545/https://www.smh.c...

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#46

Post by tivert »

hoten wrote: post #29
tivert wrote: post #24

Earlier quoted context omitted.

> I suspect this is what would be difficult to replace. A bespoke wireless sensor monitoring and communications system, integrated into an old heating/cooling system. Modern system just would not integrate into this, without a lot of work. You would have to replace everything, probably including the actual heating/cooling systems themselves. I wonder if it just integrated into a pre-existing control network: > The Co…

The number of layers added to modern programming and computer systems has gone up significantly since the 80s. It's sensible to claim that a kid from the 80s had far less to learn to be effective in the world of the 80s, than a 20s kid would need today.

> The number of layers added to modern programming and computer systems has gone up significantly since the 80s. It's sensible to claim that a kid from the 80s had far less to learn to be effective in the world of the 80s, than a 20s kid would need today.

I'm not so sure. There's a huge electronics/hardware hacking scene nowadays fueled by Raspberry Pis and Arduinos. It might actually be easier today for a kid to learn what he needed to know.

I mean, back in the 80s at best the kid probably only had the manual, a couple of programming books, and maybe a magazine subscription for reference.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#47

Post by csdvrx »

ignite wrote: post #34
csdvrx wrote: post #23

Earlier quoted context omitted.

Why replace what's not broken? Amortization of costs is one possibility. The replacement parts must be hard to obtain, but are they spending over 50k/y on old amiga parts? If not, why do you think maintenance of the old system would cost more than the new system? (+ ongoing yearly fees/maintenance) Just receiving a funding doesn't imply the need to burn the money. Any replacement using wifi +- cellular and some javas…

Why replace? So you don't have downtime. If it breaks now, everything may be off until they replace the system. That could be months of no classes, which would be much worse than spending money to replace. If you start now, and finish before it breaks, you don't have to have downtime.

Why not replace? So you don't have downtime. If it breaks now, the system is well known (30+ years) and maintained. If it's updated to something new, everything may be off until they bring back the old system.That could be months of no classes, which would be much worse than spending money to replace.

If they do nothing now, instead of taking a bet the new system will be more stable than the old one (a bet against the 30+ years odd) you don't have to have downtime.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#48

Post by c_o_n_v_e_x »

tus666 wrote: post #15

> Hopkins said the system runs on a radio frequency that sends a signal to school buildings, which reply within a matter of seconds with the status of each building. I suspect this is what would be difficult to replace. A bespoke wireless sensor monitoring and communications system, integrated into an old heating/cooling system. Modern system just would not integrate into this, without a lot of work. You would have t…

>I suspect this is what would be difficult to replace.

Nah, anything driven by relays and or pneumatic controls can be replaced with modern, low cost PLC hardware. It is common for old chemical plants to have their control systems replaced while still operating. Control is handed over from the old system to the new system (hot cutover) one control loop at a time. All you need is adequate planning.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#49

Post by uni_rule »

whalesalad wrote: post #27
tus666 wrote: post #15

> Hopkins said the system runs on a radio frequency that sends a signal to school buildings, which reply within a matter of seconds with the status of each building. I suspect this is what would be difficult to replace. A bespoke wireless sensor monitoring and communications system, integrated into an old heating/cooling system. Modern system just would not integrate into this, without a lot of work. You would have t…

What makes you say that? A software defined radio could do this pretty easily.

I don't believe one that transmits is anywhere near as cheap as one that recieves.

Re: Amiga runs Michigan schools' heating and air conditioning systems (2015)

#50

Post by uni_rule »

bcrl wrote: post #40
whalesalad wrote: post #27

Earlier quoted context omitted.

What makes you say that? A software defined radio could do this pretty easily.

It's pretty much guaranteed that any software defined radio you build today will be almost impossible to get parts for in 10 years, so your maintenance budget ends up requiring a software developer to upgrade things when parts become obsolete. At least with computers from the 1980s, the hardware is fully understood and can be much more easily repaired. There are already projects that have produced modern replacements…

At that point keep everything else intact and just replace the Amiga there with a Mr. FPGA running the same thing on hardware emulation.
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